Electric contact



Aug. 30, 1949. F. LAGER 2,480,142

ELECTRIC 'CONTAC'I' Filed Sept. 21, 1945 INVENTOR. FEED LA 65/2.

QW W A TTOR/VE Y Patented Aug. 30, 1949 UNITED STAT ES FAT-ENT F Fl CE ELECTRIC CONTACT Fred Lager, New York, N. Y.

Application September 21, 1945, Serial No. 617,904

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 2 Claims.

1 This invention relates in general to an electric contact and in particular to an electric contact for a sliding electric connection.

In numerous instances it is necessary tomake a firm electric connection between two moving bodies or between a moving body and a stationary body. In general this can be done by a simple sliding contact resembling the conventional electric brush, but where the system .is subject to vibration or where the electric contact is used in connection with delicate readings such a simple setup is unsatisfactory. For example, in copending application, Serial No. 617,902, now Patent No. 2,475,614, entitled Electrical apparatus for testing materials and filed concurrently herewith by William H. Hoppmann II and Edward C. Taylor, there is described apparatus for obtaining electric measurements from an impact tester wherein a hammer and weight assembly is dropped against an anvil. The shock of this impact may well be sufficient to disrupt normal sliding electric connections during the important impact period, and accordingly a special .shock or vibration-resistant electric connection is advisable.

It is an object of this invention to provide a vibration-resisting sliding electric connection.

Another object is to provide an auxiliary electric contact adapted to receive a moving member and to maintain electric contact therewith while permitting the moving member to continue uninterrupted along its path.

Further objects and advantages of this invention, as well as its construction, arrangement and operation, will be apparent from the following description and claims in connection With the accompanying drawing, in which,

The figure is an isometric view showing one embodiment of the new electric contact with a moving electric terminal positioned to enter the contact.

The electric contact generally designated ll comprises a contacting member I 2 mounted on an insulating frame or support I3. The contacting member I2 consists of a length of channel structure comprising the opposite side walls I6 and the bottom web ll. Blocks I of rubber or other suitable resilient material are positioned in the channel member l2 disposed lengthwise thereof, the respective blocks l5 being held abutting against the inside surfaces of respective opposite side walls Hi. This positions the blocks 15 in opposed relationship as shown, with a space l9 between opposed surfaces of the blocks.

The surface of each block I5 that is opposite the other block is coated or faced with a flexible strip I4 of electrical conducting material. Throughout the greater parts of their lengths, the opposed surfaces of strips M are relatively straight and parallel but are curved apart from each other toward their ends to provide a smooth- 1y widened entrance and exit into and out of the passage l9.

These metallic surfaces are supported and re tained in position by the backing of resilient material l5, which in turn are supported and held in position by the meta1 channel l2 having the side walls or plates l6. Under practice of the invention proven suitable, the strips I l comprise thin sheets of copper, bronze, brass or the like conductor material, each being positioned in facing relationship to its resilient block l5, and each being bent at its ends over its backing plate 16 of the channel member l2. The ends of the strips 14 are firmly attached to their side walls l6, for example by soldering, brazing or the like operation, to hold the pads l5 pressed against the inside surface of their supporting side walls l5, mechanically, and also to connect the strips 14 to the conductor material of the channel member I2 electrically.

The pads l5 are contoured as shown to position their opposed surfaces parallel to each other and spaced apart a predetermined distance when they are positioned in the channel member l2 as shown. Opposite ends of each pad I5 are bevelled as shown to widen the spacing between their opposed surfaces at their ends, to provide widened ends in the gap of space l9 between the strips M.

The described assembly comprising the channel 12 with the pads l5 and strips I4 attached thereto in the manner described, is secured to the structural support l3 by any suitable means, such as, for example, screws [8 that pass through the base web ll of the channel [2. An electric lead [4a, is connected to the electrical contact of the strips I4 and channel [2 at a suitable location.

There is also shown the moving electric terminal 20 comprising a pin 2| mounted on a supporting arm 22 and connected by means of lead 23 to a source of electric power, testing equipment, or the like. This electric terminal 20 is adapted to make electrical contact with the contacting member H by means of pin 2|, which travels sideways in a predetermined path, and which is constructed and adapted to slide between the opposed surfaces of the strips l4, and to be firmly engaged thereby. The strips l 4 are so positioned that space l9 between them is slightly smaller than the diameter of pin 2 l, thereby cansing strips M to be pressed outwardly against the resilient supporting pads [5. By this means the opposed surfaces are constantly pressed against the pin 2|, and accordingly make a firm continuous contact in spite of severe vibration which may be experienced by arm 22.

The connector II is positioned to locate the gap 19 in the path of travel of the terminal pins 2|, and the portion of the gap 19 that comprises the opposed surfaces of strips l4 parallel coincides with the portion of the path of travel of the pin 2| during which it is desired that electrical contact should be closed. The Widening of the gap I9 at its end, accomplished by the surface contours of the pads l5, provides a funneling entrance for the pin 2| into the confining parallel portion of the gap l9 at the approach end, and a gradual widening at the trailing end that causes the electrical connection to break smoothly and without severe lateral shock to the pin 2|.

This new electric contact has been particularly described and used in connection with an impact tester wherein it is desired to obtain an uninterrupted relatively small electric current and to make accurate measurements of this current. It

will be understood, however, that the new connector is adapted to be used in all cases to maintain a shock resisting electric connection between two members undergoing sliding motion with respect to each other. Where the sliding motion is in other than a straight line the space l9 between strips M will be made to conform with the direction of motion. For example, when arm 22 is undergoing accurate motion these strips l4 will be positioned in a corresponding arcuate path. As a further example, arm 22 may be adapted to revolve in a complete circle and it may be desired to maintain a continuous electric contact with this moving arm. In such a case, the strips [4 may be a pair of opposing continuous circular members.

It is to be understood that various modifications and changes can be made in this invention without departing from the spirit and scope thereof as set forth in the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. In. an electrical connector, a rigid channel member comprising electrical conductor material, a pair of blocks of resilient material positioned in the channel and disposed side by side with adjacent surfaces in opposed relationship, the blocks being contoured for their opposed surfaces to be parallel and spaced apart a predetermined distance, a strip of flexible conductor material for each block, the several strips of conductor material extending along the opposed surfaces of the blocks respectively, each strip being mechanically connected to the channel member at the ends of one of its side walls to hold its block against the wall with the wall providing a rigid backing for the block, each strip being electrically connected to the channel member at its mechanical connections to the wall thereof.

2. In an electrical connector, a rigid channel member comprising electrical conductor material, a pair of blocks of resilient material positioned in the channel and disposed side by side with adjacent surfaces in opposed relationship, the blocks being contoured for their opposed surfaces to be parallel and spaced apart with opposite ends of each surface bevelled to widen the gap between the surfaces at their ends, a strip of flexible conductor material for each block, the several strips of conductor material extending along the opposed surfaces of the blocks respectively, each strip being mechanically connected to the channel member at the ends of one of its side walls to hold its block against the wall with the Wall providing a rigid backing for the block, each strip being electrically connected to the channel member at its mechanical connections to the walls thereof.

FRED LAGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,783,665 Meuer Dec. 2, 1930 1,884,457 Wilkins Oct. 25, 1932 2,025,189 Yancheno Dec. 24, 1935 2,123,631 Koehler July 12, 1938 2,284,097 La Jone May 26, 1942 2,300,893 Hayford Nov. 3, 1942 2,331,654 Butler Oct. 12, 1943 2,361,721 Van Deventer Oct. 31, 1944 FOREIGN PATENTS Number Country Date 589,827 France Feb. 28, 1925 

